This invention relates to a method for recovering iodine from a composition containing iodine and/or iodide.
Iodine and iodine-containing compounds or iodides are important catalysts or starting compounds in chemical synthesis. Consequently, compositions containing iodine and/or iodide are produced in chemical synthesis processes, for instance in trifluoromethylation processes using CF.sub.3 I as a trifluoromethylating reagent. Compositions which contain iodine and/or iodide are also obtained in the treatment of waste gases and in the incineration of algae. It is desirable to obtain or recover the iodine from such compositions.
It is known to recover iodide from corresponding salt solutions by adding iron sulfate and hydrogen peroxide to oxidize the iodide, and then extracting the resulting iodine chloroform. This method, which is described by H. H. Weetall and W. Hertl in Inorg. Chim. Acta 104:119-23 (1985), has the disadvantage that the remaining solution is contaminated with both iron sulfate and chloroform. Furthermore, the extracted iodine must be laboriously separated from the chloroform.